Dynamo electric machine



' (No Model.) 2 Sheets-Sheet 1.

R. E. BALL.

DYNAMO ELECTRIC MACHINE.

No. 338,910. Patented Mar. 80, 1886.

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Attorneys N. PETERS PlwioLhhngnphu. wmgm. n. c,

2 Sheets-Sheet 2.

(No Model.)

R. E. BALL.

DYNAMO ELECTRIC MACHINE.

Patented Mar. 30, 1886.

WITNESSES .Attorneys N. PETERS. PhMwLillW, wamm lun. O c.

UNITED STATES PATENT OFFICE.

ROYAL E. BALL, OF NEV YORK, N. Y.

DYNAMO-ELECTRIC MACHINE.

SPEQIFICATION forming part of Letters Patent No 338,910, dated March30,1886.

Application filed April 25, 15485.

To aZZ whom it may concern.-

Be it known that I, ROYAL EDWARD BALL, a citizen of the United States,and a resident of New York, in the county of New York and State of NewYork, have invented certain new and useful Improvements inDynamoElectric Machines, of which the following is a specification.

This invention has relation to dynamoelectrio machines, and has for itsobject the pro-' vision of means for reducing weight of the frame or endpieces and the cores of the fieldmagnets without in any degree lesseningthe efficiency of the machine.

It may be here remarked that my invention is mainly designed to beapplied to that'class of dynamoelectric machines wherein the cores ofthe field-magnets consist of parallel bars wrapped with insulated wireand attached at their ends to the end blocks or frame of the machine,and having the pole-pieces attached to such bars.

My invention consists,first,in the novel manner of attaching thepole-pieces to the bars upon which the field-coils are wrapped;secondly, in the novel construction of the end pieces to which thesebars are secured; and, finally, in the novel construction, combination,and arrangement of parts, as hereinafter described and claimed.

In the accompanying drawings, Figure 1 is a perspective view of themachine complete, with the exception of the armature, its shaft, andappurtenant parts; Fig. 2-, a vertical sectional view through thelongitudinal axis of the armature-shaft, the armature and commutatorbeing removed; Fig. 3, a vertical section on the line no as of Fig. 2;Fig. 4, a plan view of one of the end frames, and Fig. 5 a detail.

A A designate the end frames of the machine. As these end frames form aportion of the field-magnet, serving to magnetically connect the twopoles of the machine, and also support the field-coils, the cores of thesame, and the pole-pieces, it is necessary to make them of a quality ofiron at once strong and soft. Usually these end frames are made of agood quality of comparatively soft cast'iron. I have found, however,thatif these end frames are so fashioned that they can be forged theymay be made much lighter than when they are Serial No. 163,480. (Nomodel.)

cast, and that they conduct the magnetism better. I therefore constructthese end frames each of a rectangular and flat plate of forged iron,and bore holes in it at each corner for the reception of the screwswhich retain the field-magnet cores in position, and a hole, A, at ornear the center for the passage of the armatureshaft. As the material ofwhich these plates are composed is too soft to afford a durable bearing,and as it is impracticable to forge ajournal of sufficient width uponthe plate and bush the same with hard metal, I find it necessary toprovide a cast or hard metal bearing for the armature-shaft. I therefore form a screw-thread within the opening A, and into said openingscrew a bush, B, of hard metal. This bush projects out some distance oneach side of the frame, and thus affords a very long bearing for theshaft. Feet B B are formed on the ends of a cross-piece, Biwhioh isscrewed at the bottom of the frame, and serves as a base for the frameand means of attachment to the floor.

0 designates the cores of the field-magnets, upon which are wrappedcoils D D. These cores consist of straight cylindrical bars of forgediron, and they are bored out with a tapered hole, 0'', running from eachend to the vicinity of the point where the pole-pieces are attached. Theobject of forming the tapered hole is for the purpose of having agreater mass of metal at the point where the magnetism is strongest, asI have found that if the bars be of the same weight at the ends as inthe vicinity of the pole-pieces an unnecessary weight is given them asthe magnetism increases from the end to the poles, and hence when thatportion of the core is of sufficient size to receive all the magnetismpossible without saturation the center portion of the core of thefield-magnet contains an unnecessary amount. These cores are four innumber-two above and two below the shaftand they are fastened to the endframes by screws E E.

In order to secure the pole-pieces, which are lettered F F, to thecircular cores 0 O, I form the said pole-pieces with semicirculargrooves on each side, into which fit the cores, and pass screws G Gthrough thecores and into these pole-pieces.

The machine, constructed as described, come bines the maximum degree ofstr'ngth and efficiency with the minimum of weight.

By making the frame A A of forged metal instead of cast I produce abetter effect, as the forged iron conducts the magnetism more readilythan cast-iron, and the frames are at the same time lighter andstronger.

Having described my invention, I claim 1. In a dynamo-electric machine,the combination, with the cores of the field-magnets, of forged iron endframes having hard-metal bearings attached thereto for the reception ofthe armature-shaft, substantially as described.

2. In a dynamo-electric machine, the combination, with the end framesand cylindrical field-magnet cores, of pole-pieces grooved to receivethe said cores and secured thereto by means of screws, substantially asdescribed.

3. In a dynamo-electric machine, the end frames, A A, composed of a fiatplate of forged iron having a central opening for the passage of thearmature-shaft and a cast-metal bush screwed into said opening,substantially as described.

4. In a dynamo-electric machine, the com.- bination of the end frames, AA, having bearings B B, the cores 0 O, havingatapered hole at each end,and the pole-pieces F F, grooved to receive said cores and securedthereto, substantially as described.

Signed at New York, in the county of New York and State of New York.

ROYAL E. BALL.

Witnesses:

GEORGE F. ESCHBAOH, J. B. CONNOLLY.

